CODEWITHSUNDEEP
javascriptanonymous-function
D Liebman
D Liebman

Reputation: 347

order of code in javascript

I have some javascript code that uses anonymous functions. I suspect, but am not sure, that the functions are called independent of their order in the code.

app_service.callbackOfSomeKind( function (result) {
    console.log("result: 1" );

} );

app_service.AnotherCallback( function (result) {
    console.log("result: 2" );

} );

how do I make sure that result 2 prints after result 1??? How do I make sure that AnotherCallback isn't even seen by JS till the code in callbackOfSomeKind is run? I was thinking of doing this:

app_service.callbackOfSomeKind( function (result) {
    console.log("result: 1" );

    app_service.AnotherCallback( function (result) {
        console.log("result: 2" );

    } );

} );

but is there a better way?

Upvotes: 0

Views: 54

Answers (1)

dandavis
dandavis

Reputation: 16726

promises are great and i recommend looking into them, but there's a way to simplify the nesting wihout major refactoring by using named callbacks instead of anons:

function someCallback(result) {
    console.log("result: 1" );
    app_service.AnotherCallback( someOtherCallback );
}

function someOtherCallback(result) {
    console.log("result: 2" );
} 


app_service.callbackOfSomeKind( someCallback );

in this manner, you can still get the execution order you need, but without nested anon callbacks that are hard to maintain and debug. i guess it's sort of a compromise between your first and second examples, but with reduced complexity and closure costs.

Upvotes: 2

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